Flip chip technology plays an important role in the packaging of semiconductor devices. A flip chip microelectronic assembly includes a direct electrical connection of face down electronic components onto substrates, such as circuit boards, using solder bumps as the interconnects. The use of flip chip packaging has dramatically grown as a result of the advantages in size, performance and flexibility flip chips have over other packaging methods.
However, the standard solder bump manufacture processes have a number of shortcomings. For example, the polyimide layer may be damaged during the process. Some contaminations would remain on the surface of the polyimide layer. The contaminations may reduce the adhesion of the underfill in the following process. Therefore, the failure rate of the overall assembly could increase.
Accordingly, there is a need for an improved structure and method to form conductive feature for a semiconductor wafer with robust electrical performance.